Answer:
1000 cm.
Explanation:
To obtain the estimated tree height :
(Height of rod / length of rod shadow) = (height of tree / length of tree shadow)
Substituting values into the formula :
(150cm / 120 cm) = (height of tree / 800 cm)
Using cross multiplication :
Height of tree * 120 = 150 * 800
Height of tree = (150 * 800) / 120
Height of tree = 120,000 / 120
Height of tree = 1000
Hence, estimate height of tree = 1000 cm
Answer:
"the force of attraction between two objects"
Explanation:
According to Newton's Universal Law of Gravitation, gravity is a force of attraction acting between objects that possess mass. The fact that we only observe gravitational attraction (as opposed to repulsion) makes gravity unique among the known forces.
Pb, if compared to Ca it is less reactive and it is a transition metal, and is highly stable alone.
Answer:
5.886 J
Explanation:
Given:
The mass of the book is, 
kg
Height of lift is, 
m
Acceleration due to gravity is, 
m/s²
Now, gain in gravitational potential energy is a function of change in position and is given as:
Here, 
is the change in gravitational potential energy.
Plug in 0.5 kg for 
, 9.81 for 
and 1.2 for 
. Solve for
Therefore, the gain in gravitational energy of the book is 5.886 J.
Answer:
I = 9.82 10⁻⁷ W / m²
Explanation:
The intensity of the sound wave is the energy of the wave between the order per unit area of the same
I = P / A = E / T A
the energy is calculated by integrating the mechanical energy in a period, where the mass is changed by the density and ‘s’ is the amplitude of the sound wave
I = ½ ρ v (w s)²
I = ½ 1.35 328 (2π 530 2.00 10⁻⁸)²
I = 221.4 (4.435 10⁻⁹)
I = 9.82 10⁻⁷ W / m²
